He served briefly in the Hellenic Navy and entered upon an academic career, before taking a post with the Greek Archaeological Service in 1929.

Many of his reforms were undone by his long-time opponent, Spyridon Marinatos, who led the Archaeological Service under the Greek junta that came to power in 1967.

[3] Papadimitriou received his school education on Syros and in Chalcis on Euboea,[4] before studying archaeology and literature at the University of Athens,[2] graduating on January 29, 1926.

[4] Papadimitriou was appointed to a post as an assistant teacher of philology in Mouzaki, in northern Greece, but resigned it in 1927 to accept an offer of a job at the University of Athens, succeeding Ioannis Sykoutris, a lecturer in Greek literature.

While on Corfu, he worked largely on Byzantine archaeology, publishing a study of the medieval Church of St. Jason and St. Sosipater [el].

[8] Between November 1933 and February 1934, Papadimitriou spent a semester at the Humboldt University of Berlin, where he studied Roman art under Gerhart Rodenwaldt [de] and attended courses by Robert Zahn, director of the Antikensammlung.

In 1940, he made a short excavation of the site of Nicopolis, the city founded by the Roman statesman Octavian in 29 BCE to commemorate his victory at the Battle of Actium.

[8] After the war, Papadimitriou was considered politically suspect by the new anti-communist government, set up following the dismantling of the armed communist organizations in February 1945.

[18] Angelos Tsoukalas [el], the governor-general of the Ionian Islands, wrote to the Ministry of Internal Affairs advising against removing Papadimitriou from Corfu, despite his role in spreading communist ideology there, on the grounds that it would create unrest among the rural population.

[20] In March 1947, Papadimitriou was moved to a supervisory position in Nafplio on the mainland, and shortly thereafter sent to the Greek embassy in Rome to assist with the repatriation of antiquities looted by Italian forces during the Axis occupation of Corfu.

Instead, following a decision of June 25, 1948,[16] he was transferred to a more prestigious post in Piraeus, the harbor of Athens, with responsibility as ephor for the region of Attica.

[21] His promotion was partly due to the support of Georgios Oikonomos [el], a professor at the University of Athens and former Minister for Education.

The news was greeted with outrage by two of Corfu's newspapers, Eleftheria and Promachos, which both expressed disgust in August 1948 that "intellectuals [who] not only did not disavow the Dekemvriana ... but also reinforced the communist betrayal" were being promoted rather than fired.

[23][d] In 1948, Papadimitriou began work on behalf of the Archaeological Society of Athens at the Sanctuary of Asclepius at Epidaurus in the Argolid,[25] which had been excavated by Panagiotis Kavvadias until the latter's death in 1928.

[27] Papadimitriou began excavation of the Sanctuary of Artemis at Brauron, also under the auspices of the Archaeological Society of Athens,[28] in eastern Attica later in 1948.

[33] The same July, he was tasked with handing over the German Archaeological Institute at Athens (DAIA), surrendered by the Nazi occupying force to the Greek Ministry of Education in 1944, to Emil Kunze, representing the government of West Germany.

Papadimitriou was appointed to lead the excavation, and organized a committee of archaeologists, consisting of Mylonas, Charitonidis, Antonios Keramopoulos and Spyridon Marinatos, to oversee the work.

[48] Papadimitriou had been tasked by the Archaeological Society of Athens with locating the cave, and made a small-scale excavation there, uncovering parts of an inscribed stele showing that it had indeed been dedicated to the god Pan and to the Nymphs in the first century BCE.

[54] Anastasios Orlandos took on his responsibilities on a temporary basis,[55] until Papadimitriou was appointed as his successor,[51] following pressure from members of the Archaeological Service and with the support of King Paul.

[51] This was also seen as a move to align the service's activity with the government's ambitions of increasing tourism, and three members of the Archaeological Council, including Marinatos and Nikolaos Kontoleon [el], resigned in protest.

[56] Papadimitrou resumed the publication of the Archaeological Bulletin, the service's journal, which had lapsed in 1938,[57] and commenced works to improve the tourist infrastructure at Delphi, including the controversial construction of a new hotel at the site.

[60] He was given the new title of Head of the Antiquities and Restoration Service of the Ministry of the Presidency in October 1960, and appointed to the revived position of Ephor General in September 1961.

[50] The newspaper Akropolis ran an article criticizing Papadimitriou's appointment on August 5, 1961, claiming that the transfer of the Archaeological Service to the Ministry of the Presidency would leave it open to a communist takeover, while the newspaper of the United Democratic Left political party expressed its hope that Papadimitriou would impress leftist ideals upon the future archaeologists of Greece.

[66] Writing in 1995, Petrakos considered Papadimitriou the second most influential of the Archaeological Service's directors, behind Kavvadias,[68] though to be more notable for his administrative than for his scholarly contributions.